Lubricating oil



Patented Mar. 27, 1951 LUBRICATING "on.

William Davey, London, England,-;iassignor -:to Shell Development Company, San Francisco, Calif., a corporation of Delaware NoDrawing. Application June2y1-947, SeriaFNo. "751,993. In Great Britain J lily 25, 1-946 .15 .Claims. (Cl. 252.48.4)

This invention relates to extreme pressure lubricants capable of withstanding high pressures at elevated temperatures under severe and adverse operating conditions. .More specifically this invention pertains to improvement of extreme pressure lubricants .byenhancing their extreme pressure properties and at the same time rendering them substantially. noncorrosive and stable, by additionrof anoveladditive thereto, in rather minor amounts.

Natural and/or synthetic. lubricantsper se are not capable .of withstanding extreme pressures at high temperatures,.highspeeds and under severe loading conditions as generally encountered in present .day lubricating such as internal combustion engines of various types, transmissio devices, certain types of gears, e. g. hypoid gears, metal fabrication .such as in cutting and drawing and the like. Under such conditions of lubrication, the protective Tfilm formed between contacting surfaces, by thelubricant, so as to prevent direct metal-to-metal contact, breaks down or ruptures, and seizure or even welding of metal'parts occurs, resulting in serious damage to'the'elements being lubricated. To overcome this serious weakness generally inherent in undoped lubricants, extreme pressure "agents-are added' which form protective films-between contacting surfaces aridwhitzh possess "among their properties theiunction of imparting film strength and oiliness to lubricants, thus preventingtheir breakdown and rupture .under the above described lubricating conditions. Y

Thexaction of extremepressureagents is largely a physico-chemical phenomena :and :this accounts primarily for theirzeifectiveness as sextreme pressure agents. These agents or ;materialsin addition-toincreasing the film strength qr lubricants, become reactive with contacting surfaces forming thereon anxalloying protective coating or film .of v.greatzstrength and thermal stability. This tenaciously adhering adsorbed protective film not only reduces frictionzbetween relatively movableparts such as encounteredin internal "combustion engines-but also acts .as an impermeable fihn whichprevents corrosive acids and other contaminants from attacking the metal surface'andithe like. To be-efiective therefore extreme pressuremust-to adegree bereactivewith contactingsurfaces and form thereon a :protective film which prevents welding .of moving parts and-aids lubrication. Since the reaction is normally. between the-additives.in the lubricant and contacting :surfaces eatwelevated temperatures of.-arouncLabout.-500 .Ceand higher,

' chlorinating organic "compounds or petroleumfractions; organic compounds containing 'phos-f the performance .of 2a fg'iven. lubricant 'must z'de pend upon :its composition, :the composition 10f the contacting surface being lubricated, :as well as the conditions :to which the combination is subjected.

.Although extreme :pressure additives to .be'

effective should ibe reactive with-.contactingisurfaces, this reactivityshould not. be corrosive .to the reactivesurface. I .Thisiis generally a serious drawback :of known extreme ,pressure agents, for serious damage to :surfaces .such .as alloy bearings andthe like-mightvresult. :Such-addi tive should also not tend-to;promote=..oxidation which generally prompts formation of corrosive acidic materials, sludge, lacquer and varnish which results in sticking and fouling of movable engine parts and the like.

Numerous compounds and mixtures of compounds have been tried as extreme pressure agents for lubricants, the best of which-'have" only m'oderatelyimproved the extreme *pressure properties of thedubricantand generally at 'the expense "of increased -corrosiveness eand instability of the lubricant. -Among such compounds may be mentioned. "organic oxygen containing compounds "such as fatty -acids;-'-esters, ketones, oxidized petroleum fractions yorganic compounds containin sulfur or oxygen and sulfur i such *as sulfurized fatty o'ils', acids, -=etc.; .organic compounds containing "chlorine 'usually obtained by phorus; organiwcompoundscontaining lead and especially such compounds when in conjunc tionwith'an-active sulfur-compound. J Of the general classes of extreme pressurecompounds enumeratedsulfur and/or halogen-containing "compounds appear to be most effective and are'there'fore preferred. Howeverthese'haveserious defects in'that most sulfur *compounds'tto' be effective "must contain a "major 'amountof sulfur in an active state which is highly 'corrosive and has 1a tendencybrseparating out and forms sludge. "Materials of this "type when in combination with halogenpontaining compounds havea deleteriouseffectby liberating"highly=:corrosive acids from the halogenated compounds" and also interfere with their"functioning-asap extreme ressure dope. Halogen-containing comj' pounds, alone, become'fhi'ghly corrosive to alloy metals such as .cadmiumesilver, .copper -lead, etc. so as .to. render Lthem .nseless afterishort periods of use.

It is an objector .thepresentinvention. to provide. .an improved extreme pressure lty-peilubri cant capable of effective lubrication under high pressures at elevated temperatures and adverse operating conditions. Still another object of this invention is to provide an improved, stable, sludge free, non-corrosive extreme pressure lubricant. Also it is an object of this invention to provide an improved extreme pressure lubricant by addition to any lubricating carrier or base a minor amount of a novel reaction product of this invention. Still another object is to form an improved non-corrosive extreme pressure additive from the reaction products of this invention. Other objects of this invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, this invention consists of features which will be hereinafter fully described and particularly pointed out in the claims, the following description settin forth in detail certain embodiments of the invention, these being illustrative of but a few variations in which the principle of the invention may be employed.

Broadly stated, this invention is directed to the use in lubricants and the like, reaction products obtained by reacting a polyhalogen containing organic carbonyl compound with alkyl, aryalkyl, aryl, cyclic thiols, selenols, and/ or telurols represented by the SH, SeH and Tel-I radicals respectively, the reaction being controlled so that the carbonyl radical reacts with the SH, SeH and/or TeH groups to form polyhalogenated thiol acetals, selenol acetals and/or telurol acetals, represented by the formula:

otherbond hydrogen or both of these bonds may.

have attached thereto organic radical having a plurality of halogen atoms. The position of the halogen atoms should be preferably such that they are as far removed from the carbonyl group as possible preferably on the end carbon atoms in relation to the position of the carbonyl group.

The polyhalogenated organic carbonyl compound may be polyhalogenated ketones or aldehydes. The following specific polyhalogenated organic carbonyl compounds which when reacted with thiol, selenol and/or telurol alcohols to form' reaction products of this invention are:

I. Polyhalogenated aliphatic ketones ofacetone, methyl acetone, methyl isobutyl ketone, methyl n-butyl ketone, methyl n-amyl ketone, methyl isoamylketone, dipropyl ketone, methyl amyl ketone, ethyl amyl ketone, diisobutyl ketone, d ibutyl ketone, methyl propyl ketone, diethyl ketone, 3-methyl heptanone, methyl vinyl ketone, pentanedione, pentanone, palmitone, laurone, stearone, pentadecanone, etc.

II. Polyhalogenated aromatic ketones ofacetophone, benzophone, benzyl' phenyl ketone, di-l benzyl ketone, etc. I.

HI. .Polyhalogenated cyclic ketones ofmesityl oxide, isophorone;cyclobutanone, cyclopent'anone,"

. benzalde'h'yde, etc.

The halogen atoms attached to the carbonyl compounds may be chlorine which is preferred or bromine and the like or the mixtures. Ha1o-' genation of these compounds may be carried out in any suitable manner. Preferred carbonyl com pounds are chloral, butyl chloral, bromal, polychlorobutanol, polyclorpentanol, trichlorobenzophenone, polychlorocyclohexanone, polychlor-- palmitone, pclychlorstearone, polychlormethyl isobutyl ketone and the like.

The thiol, selenol and/or telurol organic com pounds used to react with the polyhalogenated organic carbonyl compounds may be any organic compound containing the'SI-I, SeH and/or TeH- radicals and may include:

I. Aliphatic compounds containing substitute radical of SH, SeH and/or Tel-l ofmethyl, ethyl,

normal propyl, isopropyl, normal and isobutyl,

secondary butyl, tertiary butyl, normal amyl, isoamyl, teriary amyl, tertiary octyl, tertiary decyl, tertiary dodecyl, tertiary hexadecyl, hexyl, octyl, lauryl thiols or mercaptans, selenols, telurols and the like. II. Aromatic compounds containing SI-LSeH and/ or Tel-I groups linked directly to the aromatic nucleus or aromatic compounds in which the are-i matic nucleus is separated from the SH, SeH or. Tel-I groups by intervening carbon atoms in the chain such asphenyl, chlorophenyl, tolyl, xylyl,; naphthyl, benzyl phenylethyl, tolylpropyl mercaptans or thiols, selenols, telurols and the like. III. Unsaturated alkyl and aryl thiol, selenol and telurol compounds such asallyl; crotyl, methallyl, cinnamyl thiols, selenols and/or telurols and the like. The above thiol, selenol, and tel'urol containing compounds may be made by any suitable means or obtained from any suitable source. Thus mer captans may be extracted by a caustic alkalitreatment of petroleum hydrocarbon fractions. Also these compounds may contain various subsubstituent groups such ashalogen, acid groups and the like.

The reaction between the halogen containing organic carbonyl compounds and the tliiol,selenol and/or telurol compounds may be carried out in aqueous acid medium with the aid of slightly ele-' vated temperature." The resulting halogen bearing acetal derivative having the general formula as in column 3 may be recovered from the solu tion by suitable meanssuch as by crystallization and the like. The reaction product thus formed is of sufiicient purity so that it can beused in lubricants without further purification;

such asrecrystallization or the-like-.-

T0 'more'clearly illustrate the presentdnvem tio'n, the following examples are presen-te'd. lIt -is to be understood however that various modifica- 'ti'ons can-be resorted to without departing from 'the spirit of the invention.

Example I Example II Approximately one mole of chloralhydrate-was dissolved in about-2000 parts by-volume of Water and about 50 parts by volume of concentrated hydrochloric acid was slowly-added to the'mixture'with constant stirring. To-this mixture-approximately 2 'moles of ethyl mercaptan was added and the mixture agitated and "gently heated to about 60 C. The polychlorthioa'cetal Was'depo'sited out of'the' solution as a crystalline condensation product and recovered therefrom.

'The'fa'int odor of the parentmercaptan may be removed by recrystallization of the reaction product. The product having the appearance of white needles had a melting point of about 61 "C. and was readily soluble in mineral lubricating oil.

. EmampleJII Approximately one mole of chloralwas dissolved in about 2000 parts Joy volume of water and aboutfil) parts by volume of concentrated hydrochloric acid was slowly added to the mixture withconst'ant stirring. To this mixture approximately 2 moles of normal butyl mercaptan-was "aiddedand the mixture agitated andgently heated toabout 60 C. The polychlorthioacetal was deposited out of the solution as a crystalline condensation product and recovered therefrom.

The faint'odor of the parent 'mercaptaum'aybe removed by recrystallization of the reaction prodnot. The product having the appearance of :wh'iteneedles had a melting point of about 55 C. andwas readilysoluble in mineral lubricating 6 Example JLV Approximately one mole of chloral was dissolved in about 2000 parts'by volume'dfwaterand about 50 parts by "volume ofconceritrated hydrochloric acid was slowly added to the mixture with constant stirring. To thisniixtureapproximately 2 moles of 'isobutyl mercaptan was added and the mixture agitated and gently heatedto about C. The polychlorthioac'etal was "deposited out of the solution as a crystalline condensation product and recovered therefrom. The faint odor of the parent mercaptanm'ay 'belremoved by recrystallization o'f'the reaction product. The product havingthe appearance 'of white needles had a melting point of about 46C. and Was'readily soluble in mineral lubricating oil.

Example V Approximately one mole of chloral 'Was'dissolved in about 2000 parts bywolume-of water and about 50 parts by volume of concentrated hydrochloric acid wasslowly added to the-:mixture with constant stirring. To this mixture approximately 2 moles of phenyl mercaptan was added and the mixture agitated and gently heated to about 60 C. Thepolychlorthioacetal was deposited out of the solution as a crystalline condensation product andrecovered therefrom. The

faint odor of the parent mercaptan may be-removed by recrystallization of the reaction ,prodnot. The product having the appearance of white needles had a melting pointof about 82 C.- and was readily soluble in mineral lubricating oil.

Example VI Approximately one -mole of chloral was dissolved-in about2000 parts by volume of water addedand the mixture agitated and gently heated to'about 60 C. The polychlorthioacetal wasdeposited outof thesolution as a crystalline condensationproduct andrecovered therefrom. The faint odor of the parent 'mercaptan. may be removed by recrystallization of the reaction prodably "around about 0.25% by weight in a 150 Pennsylvania Neutral 'oil and subjected to *a-Four Ball Machine test as described in Engineering,

July 14, 1933; gave excellent extreme pressure re:

"oil. sults.

Mean gg figg g g at Coefficient of friction at various loads Per'Cent Additive in Mineral Oil N0ne 3. 14 Weld O 127 1% Reaction Product of Example III in Mineral v p 01 1 a I 0. 65 1. 50 2. 00 2. 20 0. O5 O. 07 2 1% of Reaction Product of Example IV in Mineral 0' r 0.40 0.70 1. 68 2.00 2.36 c .O l% of Reaction Product of Example V in Mineral v p 0 5 0 05 O 08 "h '0l1 a 11-04 0. 70 1140 1. 60 2.05 2.25 0. 05 0: 05 T). ()8 0108 .l "swapl- H, J

7 Other reaction products of this invention which are preferred as additives for lubricants are:

Chlorobutanal-ethyl mercaptan Chlorobutanal-phenyl mercaptan Chlorobutanal-cetyl mercaptan Chlorobutanal-ethyl selenol Chloropentanal-ethyl mercaptan Chloropentanal-butyl mercaptan Chloropentanal-benzyl mercaptan Chloropentanal-phenyl mercaptan Chloropentanal-ethyl selenol Chlorocyclobutanone-ethyl mercaptan Chlorocyclobutanone-butyl mercaptan Chlorocyclobutanone-phenyl mercaptan Chlorocyclobutyl methyl ketone-ethyl mercaptan Chlorocyclobutyl methyl ketone-butyl mercaptan Chlorocyclobutyl methyl ketone-phenyl mercaptan 1 Chlorostearone-ethyl mercaptan Chlorostearone-phenyl mercaptan Chlorostearone-benzyl mercaptan Butyl chloral-ethyl mercaptan Reaction products of this invention are highly effective extreme pressure agents for various types of lubricants and generally need not be used in amounts greater than 1% b weight. However, concentrations of as high as from 1 to may be used under certain conditions of lubrication. For other purposes, additives of this invention need only be incorporated, for example in a mineral lubricating oil or grease, in amounts of between about 0.25 and 0.5% to exert a marked improvement in the behavior of a lubricant in service involving extreme pressure.

The base lubricant or oil may be a hydrocarbon oil of the parafiins, naphthenio or asphaltic type of wide viscosity range. The oils may be refined or treated by any desirable means so as to obtain fractions suitable for specific lubricating needs. Generally SAE 10 to 50 or even higher oils may be used. In addition to natural hydrocarbon oils, natural occurring fatty materials such as fixed fatty oils and mixtures of such oils with hydrocarbon oils may be used. Also synthetic type lubricants such as polymerized olefins, copolymers of alkylene glycols and alkylene oxides, organic esters, e. g. 2-ethyl hexyl sebacate, dioctyl phthalate, trioctyl phosphate; polymeric tetrahydrofuran, polyalkyl silicon polymers and the like may be used as Well as mixtures of synthetic and natural lubricants. Also reaction products of this invention may be added to fuels, wax products, cutting compositions and the like.

Because of its synergistic eflect the reaction product of this invention can be combined with other additives in lubricants, such as, blooming agents, pour point depressants or viscosity improvers, extreme pressure agents, antifoaming agents and the like. Among the specific additives which can be used are oil-soluble detergents which include oil-soluble salts of various bases with detergent forming acids. Such bases include metal as well as organic bases. Metallic bases include those of the alkali metals, Cu, Mg, Ca, Sr, Ba, Zn, Cd, Al, Sn, Pb, Cr, Mn, Fe, Ni, Co, etc. Organic bases include various nitrogen bases as primary, secondary, tertiary and quaternary amines.

Examples of detergent forming acids are the various fatty acids of, say, 10 to 30 carbon atoms, wool fat acids, paraffin wax acids (produced by oxidation of parafi'in wax) chlorinated fatty acids,

acids, parafiin wax benzoic acids, various alkyl salicylic acids, phthalic acid mono-esters, aromatic keto acids, aromatic ether acids, .diphenols as di-(alkylphenol) sulfides and disulfides, methylene bis alkylphenols; sulfonic acids such as may be produced by treatment of alkyl aryl hydrocarbons or high boiling petroleum oils with sulfuric acid; sulfuric acid mono-esters; phosphoric, arsenic and antimony acid mono and diesters, including the corresponding thio phosphoric, arsonic and antimony acids; phosphonic and arsenic acids and the like.

Additional detergents are the alkaline earth phosphate diesters, including the thiophosphate diester; the alkaline earth diphenolates, specifically the calcium and barium salts of diphenol mono and poly sulfides.

Non-metallic detergents include compounds such as the phosphatides such as lecithin and cephlin, certain fatty oils as rapeseed oils, voltolized fatty or mineral oils and the like.

An excellent metallic detergent for the present purpose is the calcium salt of oil-soluble petroleum sulfonic acids. This may be present advantageously in the amount of about 0.025% to 0.2% sulfate ash. Also alkaline metal salts of alkyl phenol-aldehyde condensation reaction products are excellent detergents.

Antioxidants comprise several types, for example, alkyl phenols such as 2,4,6 trimethyl phenol, penta methyl-phenol, 2,4 dimethyl-6- tertiary-butyl phenol, 2,4-dimethyl-6-octyl phenol, 2,6-di-tertiary-butyl-4-methylphenol, 2,4,6 tritertiary-butyl phenol and the like; amino phenols as benzyl amino phenols; amines such as dibutyl-phenylene diamine, .diphenyl amine, phenyl-beta-naphthylamine, phenyl-alpha-naphthylamine, dinaphthyl amine.

Corrosion inhibitors or anti-rusting compounds may also be present, such as dicarboxylic acids of 16 and more carbon atoms; alkali metal and alkaline earth salts of sulfonic acids and fatty acids; organic compounds containing an acidic radical in close proximity to a nitrile, nitro or nitroso group (e. g. alpha cyano stearic acid).

Extreme pressure agents which may be used comprise: esters of phosphorus acids such as triaryl, alkyl hydroxy aryl, or aralkyl phosphates, thiophosphates or phosphites and the like; neutral aromatic sulfur compounds of relatively high boiling temperatures such as diaryl sulfides, diaryl disulfides, alkyl aryl disulfides, e. g. diphenyl sulfide, diphenol sulfide, dicresol sulfide, dixylenol sulfide, methyl butyl diphenol sulfide, di'benzyl sulfide, corresponding diand tri-sulfides, and the like; sulfurized fatty oils or esters of fatty acids and monohydric alcohols, e. g. sperm oil, jojoba oil, etc.; in which the sulfur is strongly bonded; sulfurized long chain olefins such as may be obtained by dehydrogenation or cracking of wax; sulfurized phosphorized fatty oils or acids, phosphorus acid esters having sulfurized organic radicals, such as esters of phosphoric or phosphorus acids with sulfurized hydroxy fatty acids; chlorinated hydrocarbons, such as chlorinated parafiin, aromatic hydrocarbons, terpenes, mineral lubricating oil, etc. or chlorinated esters of fatty acids containing the chlorine in position other than alpha position.

Additional ingredients may comprise oil-soluble urea or thiourea derivatives, e. g. urethanes, allophanates, carbazides, carbazones, etc.; polyisobutylene polymers, unsaturatedpolymeried esters of fatty acids and monohydric alcoholsand other high molecular Weight oil-soluble compounds.

Depending upon the additive used and conditions under which it is used, the amount of additive used may vary from, 0.11 to 2% or higher; However, substantial improvement is obtail'reddn using amounts ranging from 0.1-, to 0.5 %=in combination with polyhalogen containing organic carbonyl compoundand organic thiol, selenol and/or telurol compound. reaction. products of this invention.

The novel reaction products of this invention, addition to being. excellentlubricating oil improving agents, are potent oxidation inhibitors for fuels, natural and synthetic rubber, wax coating compositions andother organic materials.

It is to be understood that while the features of the invention have been described and illustrated in connection with certain Specific examples, the invention, however, is not to be limited thereto or otherwise restricted, except by the prior art and the scope of the appended claims.

I claim as my invention:

1. A lubricating composition consisting essentially of a major amount of a hydrocarbon oil and a minor amount of less than 1% sunicient to impart extreme pressure properties to said lubricant of trichloromethyl di(thiaethyl) methane.

2. A lubricating composition consisting essentially of a major amount of a hydrocarbon oil and a minor amount of less than 1% suflicient to impart extreme pressure properties to said lu- A XE wherein X is an element of the group consisting of S, Se and Te, A is an organic radical having a plurality of chlorine atoms and each R1 is an independently selected organic radical.

5. A lubricating composition comprising a lubricating oil and a minor amount, but sufficient to impart extreme pressure properties to said lubricant and not exceeding by weight, of a polychlorinated acetal having the general configuration H\ /SR1 /o A s R.

wherein A is an organic radical having a plurality of chlorine atoms and each R1 is an independently selected organic radical.

6. A lubricating composition comprising a lubricating oil and a minor amount, but sufficient to impart extreme pressure properties to said lubricant and not exceeding 10% by weight, of trichloromethyl di(thiaalkyl) methane.

'7. A lubricating composition comprising a In bricating oil and a minor amount, but suificient to impart extreme pressure properties to said 10c lubricanirandmotBxceading% by weight, of. trichloromethyl di(thiaaryl) methane.-

8. A lubricating composition comprising a lubricating oil and a minor amount, but suflicient to impart extreme pressure properties to said lubricant and not exceeding 10% by weight, of trichloromethyl di (.thiaaralkyll methane.

9; Alubricating composition comprising a lubricating oil and aminor amount, but sufficient to impart extremev pressure properties to saidlubricant and not exceeding 10% by weight/of,

wherein X is an element of the group consisting of S,,Se and Te, A is an organic radical having a plurality of halogen atoms and each R1 is an independently selected organic radical.

13. A lubricating composition comprising a hydrocarbon oil and a minor amount, but sufiicient to impart extreme pressure properties to said lubricant and not exceeding 10% by weight, of a polyhalogenated acetal having the general configuration wherein X is an element of the group consisting of S, Se and Te, A is an aliphatic organic radical having a plurality of halogen atoms and each R1 is an independently selected aliphatic organic radical.

14. A lubricating composition comprising a hydrocarbon oil and a minor amount, but sufiicient to impart extreme pressure properties to said lubricant and not exceeding 10% by weight, of a polyhalogenated acetal having the general configuration H\ /XR1 A X-Rr wherein X is an element of the group consisting of S, Se and Te, A is an aromatic organic radical having a plurality of halogen atoms and each R1 is an independently selected aromatic organic radical.

15. A lubricating composition comprising a hydrocarbon oil and a minor amount, but sufficient to impart extreme pressure properties to said lubricant and not exceeding 10% by weight 2,546,941 Ill of a polyhalogenated acetal having the general configuration H Number 2,223,693 I 5 2,353,170 A X-BI 2,422,341 wherein X is an element of the group consisting 2,444,525

of S, Se and Te, A is an aralkyl organic radical having a. plurality of halogen atoms and each R1 is an independently selected aralkyl organic 10 Number radical. 514,535

WILLIAM DAVEY.

REFERENCES CITED The following references are of record in th file of this patent:

OTHER REFERENCES Iowa State College Journal Science, 16, 99-102 

1. A LUBRICATING COMPOSITION CONSISTING ESSENTIALLY OF A MAJOR AMOUNT OF A HYDROCARBON OIL AND A MINOR AMOUNT OF LESS THAN 1% SUFFICIENT TO IMPART EXTREME PRESSURE PROPERTIES TO SAID LUBRICANT OF TRICHLOROMETHYL DI(THIAETHYL) METHANE. 